Ghiemstra



J. S. HO0GH|EMSTRA'.. ELECTROPNEUMAIIC ACOUSTIQ APPARATUS; APPucmon FlLiD JULY 10. I919.

1,318,1874; Patented Oct. 14,1919

2 SHEETS-$215k? 1.

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Patented Omit. 14, 1919.

2 SHEETS-SHEET 2.

- Y Agto'mey JURGEN sJonm) nooenrnmsrne, or DELFT,

ELECTROPNEUMATIG ACOUSTIC APPARATUS.

Specification of Letters Patent.

Patented Oct. 14, 1919.

Application filed July 10, 1919. Serial No. 809,918.

To all whom it may concern: Be it known that I, JURGEN SJoERD Hoo- GHIEMSTRA, a subject of the Queen of the Netherlands, residing at Delft, the Netherlands, 24 Maerten Trompstraat, have invented certain new and useful Improvements in Electropneumatic Acoustic Apparatus, of which the following is a specification.

The invention relates to a device for reinforcing the reproduction of the sounds of speech, musical tones, etc. and of acoustic vibrations in eneral for the use of the deaf. Besides tec ical properties psychological factors must be considered in devising acoustic apparatuses and are in fact much more important than for instance in the case of optical contrivances for people sufiering from poor eyesight. It is a well known fact that the deaf are the more reluctant to using acoustic contrivances as these spieuous.

The efficiency of an acoustic apparatus is almost solely determined by technical properties. The choiceof the public falls nevertheless on the device which is almost invisible when in use provided this advantage is coupled with that of a good reproduction of the acoustic vibrations.

It has been attempted to attain perfection in the one or both these respects in the construction of most pneumatic, electrical or combined electro-pneumatic apparatuses known heretofore.

The device according to the invention is an electro-pneumatic apparatus in which the parts are assembled such a way that with the exception of the microphone or soundreceiver it can be hidden in the clothes, so that besides said microphone only a small pneumatic tube can be seen. The use of hanging cord connections is avoided thereby are more (3011- greatly simplifying the device.

The characteristic feature of the construction enabling to obtain aforesaid advantages consists in the fact that the battery-holder, the telephone, and microphone are assembled to form a whole in such a way that the telephone and microphone, at least the former and the connection of the latter with the other parts, are placed above the batteryholder. The advantages derived from the compactness and consequently the greater stability and from the more simple manipulation of the combined battery-holder, telephone and microphone, give to the apparatus according to the invention a high dereference to the accompanylng drawings,

which form a part of this application and specification.

The attached drawing shows two devices according to the invention embodied in pocket-apparatuses. It is evident that the invention also relates toiother than pocketdevices as long as they bear the above characteristics.

Figure 1 is a front view partly cut away at the top and Fig. 1 shows the portions of the elements cut from the top of Fig. 1;

Fig. 2 a side view, shown slightly cut away at the top, of a pocket-apparatus, in which the microphone is placed 1n front of the apparatus at some distance from same, while Fig. 3 shows the apparatus in use.

Fig. 3 is a partial side view of a modification of the apparatus shown in Fig. 2, which differs therefrom by the use of two microphones instead of one.

Fig. 4 is a side view and Fig. 5 a front view of another pocket apparatus according to the invention, while Fig. 6 shows that part of the apparatus whiph can be seen when the apparatus is use Fig. 7 is an enlarged view of the leaf spring as shown in Fig. 4.

The device comprises a battery-holder 1 in the shape of a case as used in electric pocket-lamps. Said holder may. consist of shackles or the like between which the battery is pushed.

In the example as illustrated the case is closed at its base by a detachable cover 2,

the box-telephone 10. In the example illustrated the telephone is aflixed to the batteryholder by means of a bent piece 4 of sheet metal or the like. The plate portion of said metal piece 1 may be flat or grooved in some places to augment its rigidity. The telephone 10 forms therefore with the heavier and filled battery-holder 1 a compact solid whole; it is connected pneumatically with the outer part of the users ear.

This is done by means of a more or less flexible small tube 5, made for instance of india-rubber, as used in dictaphones and stethoscopes. Said tube 5 is connected to the space at the back of the vibrating disk of the telephone 10 by means of a tube 7 and an elbow piece 6 preferably made rotatable in the telephone-casing.

In case both the users ears have to be connected the tube 5 can be separately connected to the connection piece 6, the latter in this case being provided with two tubular pieces 7.

The tube 5 may come out of the top of the pocket and be visible from there to the ear, or said tube can be led from the connecting piece 6 under the clothes and only become visible at the neck (Fig. 3). The tube 5 is maintained in the ear by an ear-cannula.

The microphone 8 is carried by the battery-holder 1 and the telephone 10. In the example illustrated it is secured thereto by means of the same bent metal piece 4 of which one arm connects the telephone 10 to the battery. With this object in view the piece 4: is bent in U near the top of the telephone 10.

The distance between the'arms of the U is such that the edge of the pocket in which the apparatus is slipped, fits in the U (Fig. 3). The microphone system is secured to the U-piece 4 on the outside in such a way that the topedge of the highest microphone is about on a level with the curve of the U- piece 4. The microphone system may consist of a single microphone 8 (Fig. 2) or a plurality of microphones 8 and 9 as shown in Fig. 3 The U-piece 4 may be made of elastic material and the distance between the arms such that the cloth is pinched between them.

These arms may also be hinged and brought together by means of a spring.

Instead of being supported by the U-piece 4 the microphone system may be secured to the case or holder 1 by any suitable means adapted to rest on the top edge of the users pocket. The telephone 10 also may be secured to the top of the case 1 in any suitable manner. v

The invention further allows of a number of other changes in the way of attaching the device.

When the apparatus as illustrated in Figs. 1 and 2 or 3 is being used it takes the position shown in Fig. 3, so that only the microphone or microphones 8 and 9 and the tube 5 are visible.

The apparatus excels in its compactness and stability whereby vibrations capable of causing extra sounds are avoided: it is not in the least conspicuous; it is handy as the tube-cannot get entangled and-can always be concealed whereas it has the special advantages for the ear of pneumatic communi cation.

Figs. 4 to 6 show another construction, of a pocket-apparatus. The principal difierence between this and the former one illustrated in Figs. 1 to 3 lies in the special shape of the "microphone. In this case the telephone 10 is aflixed to the battery holder 1 in such a way that the front part of the casing of said telephone is not in the same plane as the front of the battery-holder 1.

The space thus left free at the top of the battery-holder is suflicient to also place the microphone 11 on the battery-holder in such a way that the front part of said microphone is on a level with the battery-holder. The whole of the apparatus with the exception of the tube 5 could therefore disappear in the users pocliet. In this case, however, the perforated disk would lie against the inside of the clothes and the reproduction of sounds would be considerably lessened.-

In the apparatus according to the invention as illustrated in Figs. 4 to 6, the soundreceiver 12 is situated on top of the micro-- phone 11 with the sound receiving-openings 13 to the fore. Between the openings 13 a number of strips 14 are provided for acoustic and practical reasons. It will of course be understood that, although the shape of the sound receiver as illustrated seems the most favorable, said shape is no part of the invention. The sound-receiver 12 can be made round or of any other shapea With a view to preventing the apparatus from falling out of the pocket, a leaf spring 15 or the like is aflixed to a pin 16 immediately under the sound-receiver 12, which spring is normally held pressed against the front part of the microphone 11.

The front wall of the battery-holder and microphone may be covered by a plate 18 to impart greater rigidity to the whole structure.

The contact button of the switch is placed on top of the sound receiver 12, whereby the telephone and microphone can be switchedv on to the battery.

The main switch is placed in such a way as to be easily within reach of the user; if

required, a regulating resistance can be' added whereby the strength of the current and consequently the increase of the sound can be regulated within certain limits.

Having fully described my invention what I claim as new and desire to secure by Letters Patent is:

1. An electro-pneumatic acoustic apparatus having a battery-holder, a microphone 1 ,3 18,87&

and a telephone, interconnectin means for these parts, a pneumatic tube or connecting the telephone with the ear, said telephone and its connection with the pneumatic tube being arranged above the batter holder, the microphone being placed in front of the telephone and separated therefrom by a narrow interval.

2. An electro-pneumatic acoustic apparatus having a battery-holder, a microphone,

i a telephone, a pneumatic tube for connecting the telephone with the ear, the telephone and its connection with said tube being disposedabove the battery holder, the microphone being arranged in front of the telephone, a U-shaped strip, one leg of which has attached to it the battery holder and the telephone, the other leg being afiiXe-d to the microphone.

3; An ele'ctro-pneumatic acoustic apparatus having a battery holder, a telephone on the battery holder, a microphone in front of the telephone, a pneumatic tube for connecting the telephone with the ear, resilient connecting means for connecting the battery holder and telephone with the microphone.

4. An electro-pneumatic acoustic a paratus having a battery-holder, a telep one and a microphone placed behind one another above the battery holder, a pneumatic tube for connecting the telephone with the ear, and a sound receiver at the upper front side of the microphone.

5. An electro-pneumatic acoustic apparatus having a battery holder, a telephone and a microphone on the battery holder behind each other, a pneumatic tube for connecting the telephone with the ear, a sound receiver at the upper front side of the microphone and means under the sound receiver for afiixing the apparatus to the clothes.

6. In electro-pneumatic acoustic apparatus, a battery holder, a telephone casing and a microphone casing on said battery holder, the front wall of one of said casings being substantially flush with that of said battery holder, and-means connected with the top portion of one of said casings for attaching the apparatus to the clothes.

In testlmony whereof I afiix my signature.

J IR-GEN SJ 0EBD HO0GHIEHSTRA. 

